Uh-oh, there might be trouble in paradise for Keith Urban and Nicole Kidman. The actress reportedly freaked out when she heard her hubby spent time alone in his tour bus with country singer, Kelsea Ballerini. Is their marriage on the rocks?

Say it ain’t so! Keith Urban, 47, and Nicole Kidman, 48, have dodged split rumors before, but a new report claims the Australian actress may finally have been pushed over the edge after Keith allegedly spent time alone in his tour bus with his tour mate, Kelsea Ballerini, 21.

UPDATE: A source close to the couple told HollywoodLife.com that these reports are “rubbish.”

Kelsea opened for Keith during his Paso Robles, Calif. tour stop on July 29, and an eyewitness caught the “Love Me Like You Mean It” singer climbing onto Keith’s bus after her opening performance, according to Starmagazine. The mag’s insider reports that Kelsea spent 20 minute s on the bus, and couldn’t stop smiling when she walked off.

During this time, Nicole was in London, preparing to shoot her next film, and reportedly blew up when she heard the news. “She was furious,” an insider tells the mag. “She called Keith as soon as she heard and demanded to know what women he’d been hanging around with in his trailer.” Eventually, the American Idol judge assured his wife that the meeting was ‘strictly professional, but Nicole is still questioning his judgment,” according to Star.

The Australian lovebirds, who married in 2006, have made a rule never to spend more than two weeks apart — but that obviously gets a little difficult with their busy schedules. Besides touring, Keith also works on American Idol, while Nicole is constantly filming big movies.

Because of Nicole’s harsh reaction to Keith and Kelsea’s tour bus meeting, friends are reportedly worried that the end of the pair’s marriage might be imminent. “Nicole always took a dim view of joining Keith on tour with their girls, because she thinks it’s not a wholesome environment,” the insider adds. “And now her mind is made up: She wants no part of that lifestyle.”

HollywoodLifers, do you think there’s trouble in paradise between Keith and Nicole?